Mattress support tilt regulator



Nov. 30, 1965 NELSON 3,220,019

MATTRESS SUPPORT TILT REGULATOR Filed Dec. 16, 1963 3 Sheets-Sheet 1FIG..1..

INVENTOR TE D NE LSON Nov. 30, 1965 T. NELSON MATTRESS SUPPORT TILTREGULATOR :5 Sheets-Sheet 2 Filed Dec. 16, 1963 FIG. 4

FIG. 3

INVENTOR.

TED NELSON FIG. 5

Nov. 30, 1965 T. NELSON 3,220,019

MATTRESS SUPPORT TILT REGULATOR Filed Dec. 16, 1965 3 Sheets-Sheet 5INVENTOR TE D N ELSON BY 4 6 a -1.43.

United States Patent 3,220,019 MATTRESS SUPPORT TILT REGULATOR TedNelson, 8638 Patterson Pass Road, Livermore, Calif. Filed Dec. 16, 1963,Ser. No. 330,720 11 Claims. (Cl. 5-62) This invention relates toadjustable tilt regulators for power tilt beds capable of tiltingmattress supports to high forward angles up to 87 and reverse tilts.More particularly, this invention relates to mattress support tiltregulators in which the maximum degree of forward and reverse tilt canbe pre-set in accordance with the requirements of the physician.

The invention provides electro-mechanical structure which adjustablylimits the tilt of power tilt beds, expressly those having mattresssupports pivotally mounted for movement to sitting, lying and reversetilt attitudes in relation to a stationary bed frame. This isaccomplished in the upward tilt position by a positive structure pre-setto the required maximum angularity and rotating with the pivoting of themattress support and striking a limit switch on the bed frame when themaximum set angularity has been reached. In the preferred embodiment thepositive structure includes a rotatable member releasably clamped arounda pivot means which rotates as the mattress support pivots. By releasingthe clamp and rotating the rotatable member about its mounting, theangle of the mattress support at which the limit switch is opened can bevaried and pre-set as desired. In the reverse tilt movement, a stop ispivotally mounted on a section of the mattress support and normallybears against a reverse limit switch to maintain the horizontalattitude. To permit a reverse tilt, the stop is pivoted to one side toclose the limit switch and permit the downward tilt of the head portionof the mattress support. In every case when the limit of rotation hasbeen accomplished, the switches are opened so that even if the controlswitch is still in engagement there will be no overload or strain on themotors.

An advantage of the invention is that the doctor or nurse can pre-setthe maximum angles through which a bed will pivot. In the past therehave been no pivot controls other than those on the outer face of thebed which cannot be seen by any one in the bed. When the controls arepatient operated, he has only his judgment in stopping the angularity oftilt at the right attitude. It is not a safe or reasonable premise toleave such matters to the judgment of a person who is either ill orconvalescing. Excessive or accidental pivoting to a forward nearvertical position or to a head down position could have seriousconsequence when a very ill patient is involved. For near vertical tiltsit is customary to strap the patient into bed and even where thisprecaution is taken to prevent injury to the patient, there is still nomeans of controlling the angularity of the bed attitude to preciselyfollow the doctors instructions.

Another advantage of the mattress support tilt regulator of theinvention is that the upward and/or reverse t-ilts permitted for thepatient can be gradually changed as the patient improves or requiresadditional therapy. The progressive increase in tilt permitted for thepatient can be arranged during a single day or over a greater period oftime. Even though an extreme tilt is required for therapy during the daytime, the maximum upward angle "ice and reverse tilt can still bedecreased during sleeping periods so that the patient will notaccidentally manipulate the controls until an undesirable angle orattitude is attained.

Another advantage of the invention is that a patient in an ill orweakened condition can be permitted to operate the tilt mechanismhimself, once the tilt regulator has been set by the nurse or doctor.This is an advantage because a patient in a serious condition would notperhaps be sufficiently aware of the movement to stop the mattresssupport from tilting beyond the limits prescribed by the doctor.Furthermore, self-help is a time saver, since the patient need not awaitand require the aid of a nurse to change the tilt. Once the degree oftilt has been pre-set, normally no aid to the patient whatever isrequired to manipulate the controls to secure any mattress supportattitude desired by the patient within the limits of the setting.

A further advantage of the tilt regulator of the invention is that themechanism is simple, easy to understand and easy to operate.

Another advantage is that the adjustable regulator is entirelymechanical, save for the limit switches, with no complicated electricalcircuits to be maintained.

Another advantage is that the regulator i compact and may be located ata central point where it will not interfere with the other functions ofthe tilt bed and is easily available for setting.

Accordingly, an object of the invention is to provide a simple andpositive regulation and control of the tilt or slant of the mattresssupport of a power tilt bed.

Another object is to provide a limit switch which operates automaticallyat a pre-selected upward angle of tilt of the mattress support of apower tilt bed to limit the angularity of the tilt.

Another object is to provide such a switch for the upward angle ofmovement and the reverse tilt of the mattress support.

A further object of the invention is to provide a limit switch thatoperates automatically when the mattress support of a power tilt bedreturns to a level or horizontal attitude.

A further object is to enable the operator to pivot the mattres supportto a reverse tilt position yet to automatically prevent a second pivotto this position upon return to a level horizontal attitude.

Another object of the invention is to provide variably positionablepositive structure in conjunction with a pivotable mattress supportwhich will strike and open a limit switch to limit the angular pivot ofthe mattress support in accordance with the positioning of said positivestructure.

Another object is to provide a rotatable member about the rotating pointof a pivotable mattress support which can be positioned to contact alimit switch on the bed frame of any angular attitude of said mattresssupport desired.

Further objects are to provide a construction of maximum simplicity,economy and ease of assembly and disassembly, also such further objects,advantages and capabilities as will fully appear and as are inherentlypossessed by the device and invention described herein.

The invention further resides in the combination, construction andarrangement of parts illustrated in the accompanying drawings, and whilethere is shown therein 3 a preferred embodiment thereof, it is to beunderstood that the same is illustrative of the invention and that theinvention is capable of modification and change and comprehends otherdetails of construction without departing from the spirit thereof or thescope of the appended claims.

In the drawings:

FIGURE 1 is a top view of the mattress support tilt.

regulator of the invention including the upward angle limit switch andthe reverse tilt limit switch, with the upward tilt set and stopped at20 above the horizontal;

FIGURE 2 is a cross-sectional view taken along the line I-I of FIGURE 1through the torque tube showing a side view of the upward angle limitswitch system, but with the switch closed and set to a maximum angle of50;

FIGURE 3 is the same view as in FIGURE 2 except that the switch is open,the mounting having rotated and the mattress support having pivoted tothe pre-selected upward angle of the setting;

FIGURE 4 is a cross-sectional view taken along the line II-II of FIGURE1 through the torque tube but showing a side view of the reverse or downtilt limit switch system with the switch. closed and the pivotablemattress support at an upward angle with the head portion raised abovethe horizontal and the footportion below the horizontal;

FIGURE 5 is a view similar to that of FIGURE 4 except that the reverseor down tilt switch is open and the pivotable mattress support is in ahorizontal attitude; and

FIGURE 6 is a view similar to that of FIGURE 4 except that the pivotablemattress support is in the reverse or downward tilt position with thehead section below the horizontal and the foot section above thehorizontal.

In the practice of the invention there is provided a powered bedhaving amattress support which pivots with respect to the frame of the bed bothto forward angles up to 87 in which the patient is in a near verticalattitude and to reverse or downward tilt attitude in which the head endof the mattress support is lower than the foot end. The bed need not beof any particular type or construction except that it is electricallyactuated and.

provided with a rotating means on the frame which rotates as themattress support pivots. For example, the

rotating means may be a part of the linkage of the tilt mechanismmounted on the frame of the power bed, and the tilt mechanism may bepowered by electrically op-.

erated hydraulic cylinders.

Referring now to the several figures of the drawings in which likenumerals indicate like parts, and particularly to FIGURES 1 to 3, thereis shown a torque tube 10 rotatably mounted on a frame member 11. Thetorque tube 10 forms part of the mattress support pivot means and.

may be mounted conveniently on the frame of the bed. A partial metalsleeve 12 is loosely fitted around the upper face of the torque tube 10.The sleeve 12 has upon its supper surface a scale 14 in angular degreescorre lated with the angle of the mattress support 15 (see.

FIGURES 4, 5 and 6) with respect to the frame 11 between. the extremeupward tilt in which the patient is nearly vertical and the horizontal.The sleeve has a button 16 permanently aflixed to its which. serves asan actuating cam against a switch arm as will be described hereinafter.It is to be noted that the relative position of the button 16 and thepointer clamp 17 has been changed in FIGURE 1 in order to betterillustrate the invention. The sleeve 12 can be easily rotated about thetorque tube 10 by fingertip pressure when unrestrained. However, apointer clamp 17 having wing screw 18 serves to position and clamp thesleeve against tube 10 in any adjusted position with respect to themaximum angle desired.

A conventional two-pole electric limit switch. 19 is mounted upside downon a transverse frame member 20 adjacent to the torque bar 10 and thesleeve 12. Operating switch blade 21 which opens and closes the switch19 has a flat cam follower 22 which extends out over the path of button16 as its rotates with tube 10, the cam follower 22 having an upturnedend so that the button 16 tends to push the lever upwardly as. it comesinto con tact. As long as the switch blade 21 is held by its spring inthe down position shown in FIGURE 2 slightly touching the sleeve, theswitch 19 is closed and the electric circuit of the bed tilt mechanismcontinues uninterrupted. However, when the button 16passes under the camfollower 22. and blade 21 is forced upwardly as shown in FIGURE 3,opening the switch 19, the electric circuit is broken and the tiltmechanism stops, even though the control button is still in contact. Thetilt of the mattress support therefore cannot pivot to an upper anglefurther than indicated by the setting of the scale 14.

Since the location of pointer clamp 17 is always the same, being held inthe threaded bore 23 by wing screw 18, it forms a point of reference forthe scale 14. The pointer can therefore be used to position the sleeve12 at a desired angular location with respect to the tube 10, using thescale 14 as a guide. The position of the button 16 is thereby also fixedwith respect to the tube 10. When the sleeve is in the clamped position,the sleeve 12 and button 16 turn with the tube 10 and will always havethe same position for a given angle of rotation on scale 14. By properlypositioning the button, the switch, and the scale with respect to eachother, the scale 14 may be adjusted to show the maximum angle of themattress support tilt which is the point at which. the limit switchfollower 22 will be contacted. In this manner the maximum angle ofupward tilt of the mattress support can be regulated. by changing theangular rotation on the sleeve opposite the pointer.

A second conventional two-pole electric switch 24 is seen in FIGURE 1adjacent to the switch 19 with blade 25 and its attached fiat contact 26extending over the torque tube 10 ata point spaced from the sleeve 12.The switch 24 is normally held in the closed position by spring means(not shown) which positions the blade 25 and contact 26 slightly abovetorque tube 10, as shown in FIG- URE 4. Stop blade 27 is mounted at oneend bypivot pin 28 for freeswing pivotal movement on mattress support 15as illustrated in FIGURES 4, 5 and 6. The stop blade 27 swings freelyfrom its pivot as gravity dictates while the mattress support 15 pivotsupwardly or downwardly above the horizontal. Usually the stop blade 27is long enough so that when the mattress support 15 is in the precisehorizontal position its butt end 30. engages the top of the bed frame11. However, in the present invention it is positioned so that the buttend 30 overhangs the operating flat contact 26 and, as mattress support15 pivots toward the horizontal, it engages the operating flat. contact26. and pushes it downwardly against torque tube 10. The length of thestop blade 27 is adjusted to touch the flat contact 26 when the mattresssupport is at a level attitude. The movement of the flat contact 26downwardly against tube 10 also moves the blade 26 downwardly and opensthe switch 24. Thus, the electric circuit of the tilt mechanism isbroken and the down ward movement is stopped, e.g., an electric circuitthrough a solenoid valve in an electrohydraulic tilt mechanism isinterrupted, all of which is not shown as it is not claimed per se as apart of this invention.

As the stop blade. 27. comes torest on the limit switch operatingcontact 26 and torque tube 10, the mattress support is also restrainedfrom further downward :movement by the torque tube itself.

When it is desired to tilt the mattress support to a reverse tiltposition with the head end lower than the foot end, the mattress supportis pivoted upwardly a short distance so that the stop blade 27 may bemanually pushed to one side making it inoperative, as in FIGURE 6. Themattress support 15 may then be pivoted in a downward angle to the fulllength of the stroke of the hydraulic piston, or to an angle of about 5from the horizontal. When the mattress support 15 is to be returned tothe horizontal, it is moved upwardly to slightly above the horizontalwhere the stop blade 27 is again free to pivot over the operatingcontact 26 in the manner before described and then moved downwardly sothat the butt end 30 operatively engages the contact 26.

In the operation of the mattress support tilt regulator of theinvention, the nurse or other operator first unclamps sleeve 12 byturning wing screw 18 to thereby release pressure of pointer clamp 17.The operator then rotates sleeve 12 about the torque tube until thedesired maximum angle of tilt for the mattress support, as specified bythe doctor, is indicated by the pointer. The wing screw 18 is thenturned up causing sleeve 12 and button 16 to be securely clamped theretoso as to rotate with the torque tube 10. The patient can now activatethe tilt mechanism, as by pushing the up button on the control panel(not shown). Upon the control button contact, the mattress supportpivots the head thereof upwardly in an arc. The relative positions ofthe switch blade 21 and its cam blade 22 and the button 16 set for amaximum of 87, is shown in FIGURE 2 as the pivot begins, the button 16being far to the left of the cam blade 22. As the mattress support 15pivots upwardly, the tube 10 rotates clockwise, bringing the button 16in contact with the cam blade 22 as shown in FIGURE 2, the switch blade21 is lifted to open the circuit of the tilt mechanism. The mattresssupport can no longer continue its upward pivot, although it may returnto a lower angle of tilt. In successive operations its maximum angle oftilt will remain the same until a setting permitting a higher or lowertilt is set on the regulator.

When the operator of the power bed wishes to return the bed to thehorizontal, he merely energizes the tilt mechanism so that the mattresssupport 15 will pivot downwardly. As the mattress support reaches thehorizontal position the stop blade 27, swinging free by gravity,contacts the flat contact 26 as seen in FIGURE 5, and forces itdownwardly until switch 24 opens the circuit of the power mechanism. Themattress support 15 is then not free to pivot to a reverse tilt fromthis, the horizontal position, until the stop blade 27 is manually movedto inoperative position to the left as shown in FIGURE 6. After stopblade 27 is moved aside, the mattress support 15 may then be pivoteddownwardly.

When the mattress support 15 has been positioned in the downward tiltattitude as shown in FIGURE 6, and it is desired to return the mattresssupport to the horizontal attitude, the power tilt mechanism is operatedin the up direction until the mattress support is a little above thehorizontal attitude. This position frees the stop blade 27 to swing freeby gravity over the operating blade 26. The mattress support 15 is thenlowered to the contact shown in FIGURE 5 and the mattress support isstopped at the horizontal. The mattress support cannot be moved to thedownward tilt unless the stop blade is manually moved as described, outof the operative position each time.

I claim:

1. In a mattress support tilt regulator the combination comprising apower tilt bed including a frame, a pivotally mounted mattress supporton said frame and operator control means for pivoting said mattresssupport with respect to said frame both to high upward angles toward thefoot of the frame and downward angles toward the head of the frame, andseparate dial means not operator controlled for limiting both the upwardand downward pivotal movement of said mattress support to pre-set angleson said dial means.

2. The mattress support tilt regulator of claim 1 in which said separatedial means for limiting both the up- Ward and downward pivot of saidmattress support is adjustable for limit settings as to angle of pivotover the entire range of pivotal movement regardless of the operatorcontrol means.

3. The mattress support tilt regulator of claim 1 in which said meansfor limiting both the upward and downward pivot of said mattress supportinterrupts the electrical circuit of the power tilt machinery when thelimiting angle of the mattress support has been attained.

4. In a mattress support tilt regulator, the combination comprising apower tilt bed including a frame, a pivotally mounted mattress supporton said frame and operator control means for pivoting said mattresssupport both to high upward angles and downward angles with respect tosaid frame, at least one limit switch mounted on the frame of said bedseparate and remotely located from said control means, and structureadjustably mounted on the pivot means of said mattress support formovement therewith to contact and open said limit switch when saidmattress support pivots to a preselected maximum angle regardless of theoperator control means.

5. In a tilt regulator, the combination comprising a frame member, pivotmeans rotatably mounted on said frame member, a limit switch mounted onsaid frame adjacent to said pivot means separate from the control means,and structure adjustably mounted on said pivot means for movementtherewith to contact and open said limit switch when said pivot meanshas rotated to the maximum pre-selected angle regardless of the controlmeans.

6. In a tilt regulator, the combination comprising a frame member, atorque tube rotatably mounted on said frame member, a rotatableselecting member rotatably mounted around said torque tube for limitingthe rotation to the angle of the setting, means for releasably clampingsaid rotatable member to said torque tube in a selected position, cammeans on said rotatable member, and a limit switch mounted on said framefor contact with said cam and stopping the rotation at the selectedposition.

7. In a mattress support tilt regulator, the combination comprising apower operated tilt bed having a frame, a mattress support pivotallymounted on said frame, power means mounted on said frame for pivotingsaid mattress support, a torque tube pivotally mounted on said frame forrotation with said mattress support, a sleeve rotatably mounted on saidtorque tube, a scale of angles indicated on said sleeve correspondingwith the angles through which said mattress support pivots, cam means onsaid sleeve, means for clamping said sleeve onto said torque tube topre-set the maximum angle of tilt, and a limit switch directly connectedto said power means mounted on said bed frame adjacent said sleevehaving a follower arm for contact with said cam, and opening said switchat the angle indicated on said scale.

8. The mattress support tilt regulator of claim 7 in which said torquetube is part of the tilt machinery of said bed.

9. The mattress support tilt regulator of claim 7 in which there are twolimit switches, one for the upward pivotal movement and one for thedownward pivotal movement.

10. In a mattress support level regulator preventing unintended downwardpivotal movement beyond the horizontal in combination a power operatedtilt bed having a frame, a mattress support pivotally mounted thereonand power means for pivoting said mattress support, a limit switchoperably connected to said power means mounted on said bed frame, and astop blade pivotally mounted at one end on said mattress support andswing freely by gravity to contact and open said limit switch when saidmattress support arrives at the horizontal position.

11. In a mattress support tilt regulator preventing unintended downwardpivotal movement beyond the horizontal in combination a power operatedtilt bed having a frame, a mattress support pivotally mounted on saidframe and power means for pivoting said mattress support with respect tosaid frame, a limit switch operably connected to saidpower means mountedon said bed frame, a stop blade pivotally mounted on said mattresssupport to swing freely by gravity to contact and open said limit switchas said mattress support pivots and a1"- rives at the horizontalposition, and means for holding said stop blade out of contact with saidlimit switch for pivotal movement of said mattress support downwardly.

FRANK B.

References Cited by the Examiner UNITED STATES PATENTS 10/ 1951 Blodgett20047 11/ 1959 Burst 5-63 11/1959 Darnell et a1 563 4/ 1964 Schaefer20047 SHERRY, Primary Examiner.

1. IN A MATTRESS SUPPORT TILT REGULATOR THE COMBINATION COMPRISING APOWER TILT BED INCLUDING A FRAME, A PIVOTALLY MOUNTED MATTRESS SUPPORTON SAID FRAME AND OPERATOR CONTROL MEANS FOR PIVOTING SAID MATTRESSSUPPORT WITH RESPECT TO SAID FRAME BOTH TO HIGH UPWARD ANGLES TOWARD THEFOT OF THE FRAME AND DOWNWARD ANGLES TOWARD THE HEAD OF THE FRAME, ANDSEPARATE DIAL MEANS NOT OPERATOR CONTROLLED FOR LIMITING BOTH THE UPWARDAND DOWNWARD PIVOTAL MOVEMENT OF SIAD MATTRESS SUPPORT TO PRE-SET ANGLESON SAID DIAL MEANS.